The present inventions relate to a yarn false twist texturing apparatus of the type wherein an advancing yarn is guided serially through a heater, a cooling device, and a twisting unit.
The purpose of texturing is to lend a substantially flat yarn a more textile-like appearance and the properties associated therewith. The flat yarn delivered to the texturing machine has a chemical substance, the so-called lubricant, adhering to the yarn in order to enable further processing of the flat yarn by the texturing machine. The lubricant leads to cohesion of the filament bundles, good sliding properties as well as antistatic behavior of the yarn. There are many such substances. What they all have in common is that, at high yarn temperatures, relatively oily vapors are produced and, as a result of the extremely fast helical twisting of the false-twisted yarn, a fine spray mist may be cast off.
From EP 0 571 975 a texturing machine is known, in which the yarn in a twist zone is conveyed through a cooling rail, which has openings in its side walls. Such openings are used to catch the cast-off oil particles and remove them from the region of the yarn. This arrangement however has the major drawback that a considerable portion of drops are cast out of the open cooling rail into the environment. In addition, oily vapors may pass substantially unimpeded out of the open cooling rail. Admittedly, in EP 0 571 975 it is proposed to connect the openings in the groove walls to a suction device but the open arrangement of the extraction openings leads to the problem that only some of the vapors are intercepted and a considerable quantity of ambient air has to be extracted at the same time. An excessively intensive extraction would however lead to an unstable yarn course inside the cooling rail.
Non-extracted vapor condenses as an oily deposit all over the machine and in the factory building, which is not only generally undesirable but also incurs cleaning costs.
Accordingly, an object of the invention is to provide a texturing machine of the type described and wherein processing of the yarn does not lead to substantial pollution by oily deposits. A further object of the invention is to provide an intensive-action cooling device which is tuned to an upstream high-temperature heater.